Molecular cloning, chromosomal localization, tissue distribution, and functional expression of the human pancreatic sodium bicarbonate cotransporter.
AuthorsAbuladze N, Lee I, Newman D, Hwang J, Boorer K, Pushkin A, Kurtz I
JournalJ Biol Chem
PubMed ID9651366
We report the cloning, sequence analysis, tissue distribution, functional expression, and chromosomal localization of the human pancreatic sodium bicarbonate cotransport protein (pancreatic NBC (pNBC)). The transporter was identified by searching the human expressed sequence tag data base. An I.M.A.G.E. clone W39298 was identified, and a polymerase chain reaction probe was ... More
Red blood cell band 3. Lysine 539 and lysine 851 react with the same H2DIDS (4,4'-diisothiocyanodihydrostilbene-2,2'-disulfonic acid) molecule.
AuthorsOkubo K, Kang D, Hamasaki N, Jennings ML
JournalJ Biol Chem
PubMed ID8294441
The band 3 protein of the red blood cell membrane catalyzes anion exchange that is inhibited by the stilbenedisulfonate derivative H2DIDS (4,4'-diisothiocyanodihydrostilbene-2,2'-disulfonic acid). There is one H2DIDS binding site per 95,000-Da band 3 polypeptide. The single bound H2DIDS molecule can react covalently with 2 different lysine residues. The 2 lysines ... More
Deoxygenation-induced cation fluxes in sickle cells: II. Inhibition by stilbene disulfonates.
AuthorsJoiner CH
JournalBlood
PubMed ID2364172
Deoxygenation-induced cation movements in sickle cells were inhibited 80% to 85% by the anion transport inhibitor, 4,4'-diisothiocyano-2,2'disulfostilbene (DIDS). Morphologic sickling was not altered by DIDS treatment, demonstrating that morphologic sickling was not sufficient to produce cation leaks in sickle cells. DIDS inhibition of deoxygenation-induced cation flux was not affected when ... More
Effect of potassium depletion of Hep 2 cells on intracellular pH and on chloride uptake by anion antiport.
AuthorsMadshus IH, Tønnessen TI, Olsnes S, Sandvig K
JournalJ Cell Physiol
PubMed ID3571337
The effect of K+ depletion of Hep 2 cells on ion fluxes, internal pH, cell volume, and membrane potential was studied. The cells were depleted of K+ by incubation in K+-free buffer with or without a preceding exposure to hypotonic medium. Efflux of K+ in cells not exposed to hypotonic ... More
Transfer of band 3, the erythrocyte anion transporter, between phospholipid vesicles and cells.
AuthorsNewton AC, Cook SL, Huestis WH
JournalBiochemistry
PubMed ID6661430
Band 3, the anion transport protein of human erythrocyte membranes, can be transferred from cells to liposomes and from liposomes back to cell membranes, retaining function and native orientation. After incubation with cells, sonicated phosphatidylcholine vesicles bind a transmembrane protein that comigrates with band 3 on sodium dodecyl sulfate-polyacrylamide gels. ... More
Anion transport inhibitors as suppressors of Plasmodium falciparum growth in in vitro cultures.
AuthorsCabantchik ZI, Kutner S, Krugliak M, Ginsburg H
JournalMol Pharmacol
PubMed ID6346050
Identification of band 3-like proteins and Cl-/HCO3- exchange in isolated cardiomyocytes.
AuthorsPucéat M, Korichneva I, Cassoly R, Vassort G
JournalJ Biol Chem
PubMed ID7836397
'The identification of the protein that exerts the function of Cl-/HCO3- exchange is still unresolved in cardiac tissue. We have addressed this issue by using a multiple technical approach. Western blotting analysis with an antibody raised against human erythroid whole band 3 protein, the so-called protein that mediates the Cl-/HCO3- ... More
Chlorotoxin inhibits glioma cell invasion via matrix metalloproteinase-2.
AuthorsDeshane J, Garner CC, Sontheimer H
JournalJ Biol Chem
PubMed ID12454020
'Primary brain tumors (gliomas) have the unusual ability to diffusely infiltrate the normal brain thereby evading surgical treatment. Chlorotoxin is a scorpion toxin that specifically binds to the surface of glioma cells and impairs their ability to invade. Using a recombinant His-Cltx we isolated and identified the principal Cltx receptor ... More
VDAC-dependent permeabilization of the outer mitochondrial membrane by superoxide induces rapid and massive cytochrome c release.
AuthorsMadesh M, Hajnóczky G
JournalJ Cell Biol
PubMed ID11739410
'Enhanced formation of reactive oxygen species (ROS), superoxide (O2*-), and hydrogen peroxide (H2O2) may result in either apoptosis or other forms of cell death. Here, we studied the mechanisms underlying activation of the apoptotic machinery by ROS. Exposure of permeabilized HepG2 cells to O2*- elicited rapid and massive cytochrome c ... More
Enhancement of anion permeability in lecithin vesicles by hydrophobic proteins extracted from red blood cell membranes.
AuthorsRothstein A, Cabantchik ZI, Balshin M, Juliano R
JournalBiochem Biophys Res Commun
PubMed ID1147918
Heterogeneity of brain benzodiazepine receptors demonstrated by [3H]propyl beta-carboline-3-carboxylate binding.
AuthorsHirsch JD, Kochman RL, Sumner PR
JournalMol Pharmacol
PubMed ID6287198
Evaluation of structural interdependence of membrane-spanning and cytoplasmic domains of band 3.
AuthorsAppell KC, Low PS
JournalBiochemistry
PubMed ID7093237
Urokinase immobilized on erythrocytes.
AuthorsKitao T, Hattori K
JournalThromb Haemost
PubMed ID6996207
pH recovery from intracellular alkalinization in Retzius neurones of the leech central nervous system.
AuthorsFrey G, Schlue WR
JournalJ Physiol
PubMed ID8331595
'1. Neutral-carrier pH-sensitive microelectrodes were used to investigate intracellular pH (pHi) recovery from alkalinization in leech Retzius neurones in Hepes- and in CO2-HCO3(-)-buffered solution. The Retzius neurones were alkaline loaded by the addition and subsequent removal of 16 mM acetate, by changing from 5% CO2-27 mM HCO3- to 2% CO2-11 ... More
Structural and functional characterization of band 3 from Southeast Asian ovalocytes.
AuthorsMoriyama R, Ideguchi H, Lombardo CR, Van Dort HM, Low PS
JournalJ Biol Chem
PubMed ID1464593
'To determine why deletion of the nine amino acids joining the membrane and cytoplasmic domains of band 3 from Southeast Asian ovalocytes (SAO) renders the erythrocytes rigid, we compared the structural and functional properties of SAO and normal band 3. Calorimetric data, inhibitor binding studies, and anion transport assays all ... More
Na+, K+, and H+/HCO3- transport in submandibular salivary ducts. Membrane localization of transporters.
AuthorsZhao H, Xu X, Diaz J, Muallem S
JournalJ Biol Chem
PubMed ID7642647
'The mechanisms mediating transepithelial ion transport in salivary ducts were characterized and localized by studying the regulation of [Na+]i, [K+]i, and pHi in isolated intralobular ducts and perfused main ducts of the submandibular salivary gland. A new procedure was developed for the rapid preparation of intralobular ducts. Measurements of pHi ... More
The mechanisms of inhibition of anion exchange in human erythrocytes by 1-ethyl-3-[3-(trimethylammonio)propyl]carbodiimide.
AuthorsWerner PK, Reithmeier RA
JournalBiochim Biophys Acta
PubMed ID2454665
'Treatment of human erythrocytes with the membrane-impermeant carbodiimide 1-ethyl-3-[3-(trimethylammonio)propyl]carbodiimide (ETC) in citrate-buffered sucrose leads to irreversible inhibition of phosphate-chloride exchange. The level of transport inhibition produced was dependent on the concentration of citrate present during treatment, with a maximum of approx. 60% inhibition. [14C]Citric acid was incorporated into Band 3 ... More
Regulation of intracellular pH in the perfused heart by external HCO3- and Na(+)-H+ exchange.
AuthorsGrace AA, Kirschenlohr HL, Metcalfe JC, Smith GA, Weissberg PL, Cragoe EJ, Vandenberg JI
JournalAm J Physiol
PubMed ID8393626
'Both Na(+)-dependent HCO3- influx and the Na(+)-H+ antiport have been shown to contribute to recovery from intracellular acidosis in avian and mammalian cardiac tissue. We have investigated the participation of these mechanisms in the recovery of intracellular pH (pHi) after an acid load in the Langendorff-perfused ferret heart. pHi was ... More
4-aminopyridine decreases progesterone production by porcine granulosa cells.
AuthorsLi Y, Ganta S, von Stein FB, Mason DE, Mitchell BM, Freeman LC
JournalReprod Biol Endocrinol
PubMed ID12740033
'BACKGROUND: Ion channels occur as large families of related genes with cell-specific expression patterns. Granulosa cells have been shown to express voltage-gated potassium channels from more than one family. The purpose of this study was to determine the effects of 4-aminopyridine (4-AP), an antagonist of KCNA but not KCNQ channels. ... More
The relationship between valinomycin-induced alterations in membrane phospholipid fatty acid turnover, membrane potential, and cell volume in the human erythrocyte.
AuthorsDise CA, Goodman DB
JournalJ Biol Chem
PubMed ID3972807
'The relationship between alterations in transmembrane potential, cell volume, and phospholipid fatty acid turnover has been examined in human erythrocytes by treating the cells with the monovalent cation ionophore valinomycin. Valinomycin increases the cellular uptake of tetra[3H]phenylphosphonium ion by erythrocytes, indicating membrane hyperpolarization, and causes net loss of potassium chloride ... More
Regulation of intracellular pH in single rat zona glomerulosa cells.
AuthorsShepherd RM, Williams GH, Quinn SJ
JournalAm J Physiol
PubMed ID1310209
'The cytosolic pH (pHi) regulation of rat adrenal zona glomerulosa (ZG) cells was studied using single-cell spectrofluorimetry. Basal pHi was similar for cells incubated in the absence or presence of the HCO3(-)-CO2 buffering system. In the absence of HCO3-, inhibition of the Na(+)-H+ exchanger by dimethylamiloride (DMA) or removal of ... More
Initial stages of influenza hemagglutinin-induced cell fusion monitored simultaneously by two fluorescent events: cytoplasmic continuity and lipid mixing.
AuthorsSarkar DP, Morris SJ, Eidelman O, Zimmerberg J, Blumenthal R
JournalJ Cell Biol
PubMed ID2745545
'We have monitored the mixing of both aqueous intracellular and membrane-bound fluorescent dyes during the fusion of human red blood cells to influenza hemagglutinin-expressing fibroblasts using fluorescence spectroscopy and low light, image-enhanced video microscopy. The water-soluble fluorescent dye, N-(7-nitrobenzofurazan-4-yl)taurine, was incorporated into intact human red blood cells. The fluorescence of ... More
Effects of osmotic stresses on isolated rat hepatocytes. II. Modulation of intracellular pH.
AuthorsGleeson D, Corasanti JG, Boyer JL
JournalAm J Physiol
PubMed ID2305896
'To assess the roles of acid-base transport systems in cell volume regulation in rat hepatocytes, intracellular pH (pHi) was measured in subconfluent monolayers loaded with 2''-7''-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF) after exposure to hypotonic and relative hypertonic media, interventions that stimulate regulatory volume decrease (RVD) and increase (RVI), respectively. During RVD, pHi decreased ... More
The role of anions in pH regulation of Leishmania major promastigotes.
AuthorsVieira L, Lavan A, Dagger F, Cabantchik ZI
JournalJ Biol Chem
PubMed ID8206930
'The pH regulation of Leishmania major promastigotes was studied as a function of the ionic composition of the medium and in response to acid and alkali load. Intracellular pH (pHi) was monitored by on-line ratio fluorescence using the fluorescence-dependent pH indicator 2',7'-bis-(carboxyethyl)-5,6-carboxyfluorescein (BCECF). In Cl(-)-based medium (pH 7.4, 30 degrees ... More
An anion binding site that regulates the glutamate transporter of synaptic vesicles.
AuthorsHartinger J, Jahn R
JournalJ Biol Chem
PubMed ID8226829
'Glutamate, the major excitatory neurotransmitter of the mammalian central nervous system, is stored in synaptic vesicles and released by exocytosis upon depolarization of the presynaptic nerve terminal. Synaptic vesicles possess an active glutamate-specific transporter that is driven by an electrochemical proton gradient across the vesicle membrane and requires chloride for ... More
Analysis of ion transport perturbations caused by hu MDR 1 protein overexpression.
AuthorsHoffman MM, Roepe PD
JournalBiochemistry
PubMed ID9287158
'In previous work [Luz et al. (1994) Biochemistry 33, 7239-7249; Roepe et al. (1994) Biochemistry 33, 11008-11015] we measured changes in Cl- and HCO3--dependent pHi regulation for LR73 Chinese hamster ovary fibroblasts overexpressing mu MDR 1 protein. However, only one clonal cell line overexpressing the protein but not previously exposed ... More
Out-of-equilibrium pH transients in the guinea-pig ventricular myocyte.
AuthorsLeem CH, Vaughan-Jones RD
JournalJ Physiol
PubMed ID9575296
'1. Following an intracellular alkali load (imposed by acetate prepulsing in CO2/HCO3- buffer), intracellular pH (pHi) of the guinea-pig ventricular myocyte (recorded from intracellular SNARF fluorescence) recovers to control levels. Recovery has two phases. An initial rapid phase (lasting up to 2 min) is followed by a later slow phase ... More
Anion exchanger isoform 2 operates in parallel with Na(+)/H(+) exchanger isoform 1 during regulatory volume decrease of human cervical cancer cells.
AuthorsShen MR, Wilkins RJ, Chou CY, Ellory JC
JournalFEBS Lett
PubMed ID11852051
'Intracellular pH (pH(i)) homeostasis was investigated in human cervical cancer SiHa cells undergoing regulatory volume decrease (RVD) to determine which transport systems were involved. Using isoform-specific primers, mRNA transcripts of Na(+)/H(+) exchanger isoform 1 (NHE1) and isoform 3 were identified by reverse transcriptase polymerase chain reaction (RT-PCR) and the results ... More
The effect of apical and basolateral lipids on the function of the band 3 anion exchange protein.
Authorsvan't Hof W, Malik A, Vijayakumar S, Qiao J, van Adelsberg J, Al-Awqati Q
JournalJ Cell Biol
PubMed ID9362512
'Although many polarized proteins are sorted to the same membrane domain in all epithelial tissues, there are some that exhibit a cell type-specific polarity. We recently found that band 3 (the anion exchanger AE1) was present in the apical membrane of a renal intercalated cell line when these cells were ... More
Characterization of a chloride conductance activated by hyperpolarization in Aplysia neurones.
AuthorsChesnoy-Marchais D
JournalJ Physiol
PubMed ID6415266
'A voltage-clamp study was made of some properties of the non-synaptic hyperpolarization-activated Cl- conductance recently described in Aplysia neurones loaded with Cl- ions (Chesnoy-Marchais, 1982). The experiments were performed on an identified family of neurones, which present cholinergic responses allowing an easy measurement of the equilibrium potentials of Cl- (ECl) ... More
Isolation and characterization of mitochondrial F(1)-ATPase from crayfish (Orconectes virilis) gills.
AuthorsLi Z, Neufeld GJ
JournalComp Biochem Physiol B Biochem Mol Biol
PubMed ID11207445
'A soluble F(1)-ATPase was isolated from the mitochondria of crayfish (Orconectes virilis) gill tissue. The maximal mitochondrial disruption rate (95%) was obtained by sonicating for 4 min at pH 8.6. A 15-fold purification was estimated. The properties for both soluble and membrane-bound enzyme were studied. Both enzyme forms were stable ... More
Forskolin-induced clearance of the fluorescent dye sulforhodamine from rat parotid intralobular duct lumen: visualization of the secretory function under a confocal laser scanning microscope.
AuthorsNakamoto T, Hirono C, Sugita M, Takemoto K, Iwasa Y, Akagawa Y, Shiba Y
JournalJ Membr Biol
PubMed ID12533784
'Cyclic AMP evokes fluid secretion with bicarbonate in exocrine ducts. Clearance of fluorescent dyes from rat parotid intralobular ducts by forskolin was visualized as a fluorescence change in the duct luminal space by optical sectioning under a confocal laser scanning microscope to clarify the secretory function in the ducts. When ... More
Facilitated phosphatidylcholine flip-flop across erythrocyte membranes using low molecular weight synthetic translocases.
AuthorsBoon JM, Smith BD
JournalJ Am Chem Soc
PubMed ID11427044
'The transmembrane distribution of phospholipids plays an important regulatory role in human erythrocytes. Membrane-bound translocase enzymes maintain an asymmetric phospholipid distribution across the membrane monolayers by promoting transmembrane diffusion or flip-flop. Mechanistic understanding of the flip-flop process is weak at the molecular level. Recently, we discovered that amide and sulfonamide ... More
An alkaline pH-activated Cl(-)-anion exchanger regulates pH homeostasis in fibroblasts.
AuthorsLin PY, Ahluwalia M, Gruenstein E
JournalAm J Physiol
PubMed ID1689112
'Alkalinization of the cytoplasm in human fibroblasts activates Cl- efflux. The pathway of Cl- efflux is inhibited by 4,4''-diisothiocyanostilbene-2,2''-disulfonic acid (DIDS) or by removal of Cl- from the extracellular medium, but it is insensitive to the Cl(-)-cation cotransport inhibitor bumetanide. These data indicate that the alkali-stimulated Cl- pathway is a ... More
Partial characterization of the glucose transport activity in the Golgi-rich fraction of fat cells.
AuthorsSmith MM, Robinson FW, Watanabe T, Kono T
JournalBiochim Biophys Acta
PubMed ID6540601
'The glucose transport activity solubilized from the basal and plus insulin forms of the Golgi-rich fraction of adipocytes was partially characterized, and the results were compared with those of the activity obtained from the plus insulin form of the plasma membrane-rich fraction. The transport activity was determined in a cell-free, ... More
An apical K(+)-dependent HCO(3)- transport pathway opposes transepithelial HCO(3)- absorption in rat medullary thick ascending limb.
AuthorsWatts BA, Good DW
JournalAm J Physiol Renal Physiol
PubMed ID15026301
'Absorption of HCO(3)(-) in the medullary thick ascending limb (MTAL) is mediated by apical membrane Na(+)/H(+) exchange. The identity and function of other apical acid-base transporters in this segment have not been defined. The present study was designed to examine apical membrane HCO(3)(-)/OH(-)/H(+) transport pathways in the rat MTAL and ... More
Ammonium action on post-synaptic inhibition in crayfish neurones: implications for the mechanism of chloride extrusion.
AuthorsAickin CC, Deisz RA, Lux HD
JournalJ Physiol
PubMed ID7143250
'1. The reversal potential of the Cl(-)-dependent, inhibitory post-synaptic potential (E(i.p.s.p.)) was measured in the isolated crayfish stretch receptor neurone using two intracellular micro-electrodes. The difference between E(i.p.s.p.) and the resting membrane potential (E(m)), the i.p.s.p. driving force, was reversibly decreased by addition of NH(3)/NH(4) (+), and the mechanism of ... More
Band 3 Memphis variant II. Altered stilbene disulfonate binding and the Diego (Dia) blood group antigen are associated with the human erythrocyte band 3 mutation Pro854-->Leu.
AuthorsBruce LJ, Anstee DJ, Spring FA, Tanner MJ
JournalJ Biol Chem
PubMed ID8206915
'Band 3 Memphis is a commonly occurring polymorphic form of the human red cell anion transporter (band 3, AE1). Band 3 Memphis migrates more slowly on an SDS-polyacrylamide gel than normal band 3 and results from a point mutation Lys56-->Glu. Two types of band 3 Memphis, variants I and II, ... More
Transport of fluorescent phospholipid analogues from the erythrocyte membrane to the parasite in Plasmodium falciparum-infected cells.
AuthorsHaldar K, de Amorim AF, Cross GA
JournalJ Cell Biol
PubMed ID2661561
'The asexual development of the human malaria parasite Plasmodium falciparum is largely intraerythrocytic. When 1-palmitoyl-2-[6-[(7-nitro-2-1,3-benzoxadiazole-4-yl)amino]caproyl] phosphatidylcholine (NBD-PC) was incorporated into infected and uninfected erythrocyte membranes at 0 degrees C, it remained at the cell surface. At 10 degrees C, the lipid was rapidly internalized in infected erythrocytes at all stages ... More
Changes in luminal flow rate modulate basal and bradykinin-stimulated cell [Ca2+] in aortic endothelium.
AuthorsOliver JA, Chase HS
JournalJ Cell Physiol
PubMed ID1313820
'Hemodynamic forces influence many endothelial cell functions. The coupling between hemodynamic forces and cell function could be mediated by mechano-sensitive ion channels present in the plasma membrane of endothelial cells. Because one of these channels is permeable to Ca2+, we tested whether hemodynamic forces influence endothelial cell Ca2+ ([Ca2+]i). Bovine ... More
Location of the maltosyl isothiocyanate binding site on the human erythrocyte glucose transporter.
AuthorsShelton RL, Langdon RG
JournalBiochemistry
PubMed ID4040390
'The covalent affinity probe maltosyl isothiocyanate (MITC) has been used previously to identify the glucose transporter of human erythrocytes as a component of band 3. By use of limited proteolysis, the site on the Mr 100 000 protein to which MITC attaches has been localized to a 17 000-dalton region ... More
Rat liver microsomal glucose-6-P translocase. Effect of physiological status on inhibition and labeling by stilbene disulfonic acid derivatives.
AuthorsZoccoli MA, Hoopes RR, Karnovsky ML
JournalJ Biol Chem
PubMed ID6288677
'Intact microsomes from groups of fed, fasted, glucocorticoid-treated (triamcinolone) and diabetic (alloxan) rats were reacted with 4,4''-diisothiocyanostilbene-2,2''-disulfonic (DIDS), a specific inhibitor of microsomal glucose-6-P translocase. The concentrations that inhibit by 50% were 41 +/- 2, 31 +/- 1, 39 +/- 4, and 18 +/- 1 microM (mean +/- S.E.; n ... More
Specificity and properties of the nucleotide carrier in chromaffin granules from bovine adrenal medulla.
AuthorsWeber A, Westhead EW, Winkler H
JournalBiochem J
PubMed ID6307271
'1. The influence of various substances on the uptake of [3H]ATP and [14C]-noradrenaline into isolated bovine chromaffin granules was investigated. The carrier-mediated [3H]ATP uptake is specifically inhibited by SO42-, PO43- and phosphoenolpyruvate. Compounds with carboxylic acid or sulphonic acid groups had no significant inhibitory effects on either uptake. 2. 35SO42-, ... More
Influence of acid secretory state on Cl(-)-base and Na(+)-H+ exchange and pHi in isolated rabbit parietal cells.
AuthorsSeidler U, Roithmaier S, Classen M, Silen W
JournalAm J Physiol
PubMed ID1310223
'Parietal cell apical proton secretion is accompanied by apical Cl- secretion, K+ cycling, and the generation of intracellular base. We examined the ability of the parietal cell to maintain intracellular pH (pHi) during its transformation from the resting to the stimulated state and evaluated the ion transport mechanisms involved in ... More
Intracellular pH regulation in cultured astrocytes from rat hippocampus. II. Electrogenic Na/HCO3 cotransport.
AuthorsBevensee MO, Apkon M, Boron WF
JournalJ Gen Physiol
PubMed ID9379176
'In the preceding paper (Bevensee, M.O., R.A. Weed, and W.F. Boron. 1997. 110: 453-465.), we showed that a Na-driven influx of HCO causes the increase in intracellular pH (pH) observed when astrocytes cultured from rat hippocampus are exposed to 5% CO/17 mM HCO. In the present study, we used the ... More
Sodium-dependent Cl-/HCO3- exchange in patients with chronic renal failure: correlation with renal function.
AuthorsTepel M, Nesbit O, Tokmak F, Zidek W
JournalKidney Int
PubMed ID9461103
'To investigate the effects of uremia on cellular function the activity of the sodium-dependent chloride-bicarbonate exchanger (sodium-dependent Cl-/HCO3- exchanger) and the sodium-independent chloride-bicarbonate exchanger (sodium-independent Cl-/HCO3- exchanger) were examined in lymphocytes from 25 patients with mild chronic renal failure, 9 patients with end-stage chronic renal failure on regular hemodialysis, and ... More
Ca(2+)-activated K+ transport in erythrocytes. Comparison of binding and transport inhibition by scorpion toxins.
AuthorsBrugnara C, De Franceschi L, Alper SL
JournalJ Biol Chem
PubMed ID7682555
'We have investigated the interactions of synthetic charybdotoxin (ChTX), synthetic iberiotoxin (IbTX), and recombinant mutant ChTX peptides with the Ca(2+)-activated K+ channel (Gardos pathway) in human and rabbit erythrocytes. We measured the binding of 125I-ChTX to erythrocytes, the displacement of bound 125I-ChTX by unlabeled toxin and analogs, and then compared ... More
Rat hepatocytes exhibit basolateral Na+/HCO3- cotransport.
AuthorsRenner EL, Lake JR, Scharschmidt BF, Zimmerli B, Meier PJ
JournalJ Clin Invest
PubMed ID2539394
'Primary cultures and plasma membrane vesicles were used to characterize Na+ and HCO3- transport by rat hepatocytes. Na+ uptake into hepatocytes was stimulated approximately 10-fold by 25 mM extracellular HCO3-.HCO3--stimulated Na+ uptake was saturable, abolished by 4-acetamido-4''-isothiocyano-2,2''-disulfonic acid stilbene (SITS), and unaffected by amiloride or Cl- removal. Neither propionate nor ... More
Kinetics of conformational changes associated with inhibitor binding to the purified band 3 transporter. Direct observation of allosteric subunit interactions.
AuthorsSalhany JM, Cordes KA, Schopfer LM
JournalBiochemistry
PubMed ID8338838
'Subunit interaction effects were identified for isolated human erythrocyte band 3, the anion exchanger, by observing both static and stopped-flow kinetic protein fluorescence changes associated with inhibitor binding to the intramonomeric stilbenedisulfonate site. We measured the rate of conformational changes associated with reversible binding of H2DIDS (4,4''-diisothiocyanodihydrostilbene-2,2''-disulfonate). The rate of ... More
Cyanine dye fluorescence used to measure membrane potential changes due to the assembly of complement proteins C5b-9.
AuthorsWiedmer T, Sims PJ
JournalJ Membr Biol
PubMed ID4032456
'The fluorescent potentiometric indicator diS-C3-(5) has been used to investigate changes in membrane potential due to assembly of the C5b-9 membrane attack complex of the complement system. EAC1-7 human red blood cells and resealed erythrocyte ghosts--bearing membrane-assembled C5b67 complexes--were generated by immune activation in C8-deficient human serum. Studies performed with ... More
Interactions between mutant and wild-type band 3 subunits in hereditary Southeast Asian ovalocytic red blood cell membranes.
AuthorsSalhany JM, Schopfer LM
JournalBiochemistry
PubMed ID8555182
'Red cell membranes from individuals with Southeast Asian ovalocytosis (SAO) contain approximately equal proportions of wild-type band 3 and a mutant SAO band 3 which lacks residues 400-408. It is known that the Vmax for anion exchange in SAO cells is reduced by about 50%, that SAO band 3 does ... More
Nonmediated flip-flop of anionic phospholipids and long-chain amphiphiles in the erythrocyte membrane depends on membrane potential.
AuthorsHaest CW, Oslender A, Kamp D
JournalBiochemistry
PubMed ID9283078
'The nonmediated inward translocation (flip) of the anionic fluorescent N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)- (NBD-)labeled phospholipid phosphatidylmethanol (PM) from the outer to the inner membrane leaflet of human erythrocytes and vice versa depends on membrane potential. Interestingly, inside-positive potentials due to chloride gradients and the native chloride conductance of the cells resulted in an ... More
Transporters involved in regulation of intracellular pH in primary cultured rat brain endothelial cells.
AuthorsTaylor CJ, Nicola PA, Wang S, Barrand MA, Hladky SB,
JournalJ Physiol
PubMed ID16916905
'Fluid secretion across the blood-brain barrier, critical for maintaining the correct fluid balance in the brain, entails net secretion of HCO(3)(-), which is brought about by the combined activities of ion transporters situated in brain microvessels. These same transporters will concomitantly influence intracellular pH (pH(i)). To analyse the transporters that ... More
Intracellular pH regulation in isolated rat bile duct epithelial cells.
AuthorsStrazzabosco M, Mennone A, Boyer JL
JournalJ Clin Invest
PubMed ID2022723
'To evaluate ion transport mechanisms in bile duct epithelium (BDE), BDE cells were isolated from bile duct-ligated rats. After short-term culture pHi was measured with a single cell microfluorimetric set-up using the fluorescent pHi indicator BCECF, and calibrated with nigericin in high K+ concentration buffer. Major contaminants were identified using ... More
Identification and partial purification of the erythrocyte L-lactate transporter.
AuthorsPoole RC, Halestrap AP
JournalBiochem J
PubMed ID1590773
'1. Intact erythrocytes were incubated with 100 microM-4,4''-di-isothiocyanostilbene-2,2''-disulphonate (DIDS), a concentration sufficient to inhibit lactate transport irreversibly by 65%. DIDS-labelled proteins were detected by immunoblotting of erythrocyte membrane proteins with an anti-DIDS antibody. Labelled polypeptides of 35-45 kDa in rat erythrocytes, and of 40-50 kDa in rabbit and guinea pig ... More
Hemisodium, a novel selective Na ionophore. Effect on normal human erythrocytes.
AuthorsKaji DM
JournalJ Gen Physiol
PubMed ID1613483
'Hemisodium is a novel Na ionophore that belongs to the class of compounds called cryptands. These compounds possess an electron-rich cavity for binding of cations and are conformationally organized during synthesis to favor the selective binding of one cation over another. In media containing 145 mM NaCl and 5 mM ... More
Studies on the Ca2+-induced lysis of platelet alpha-granules.
AuthorsVan der Meulen J, Grinstein S
JournalArch Biochem Biophys
PubMed ID6347066
'Platelet alpha-granules have been reported to lyse upon addition of submillimolar Ca2+ (J. Van der Meulen and S. Grinstein, J. Biol. Chem. 257, 5190). Similar observations in parotid granules have been attributed to extensive lipid hydrolysis. Experiments were performed to assess the role of lipases and proteases in Ca2+-induced lysis ... More
Reversible and irreversible inhibition, by stilbenedisulphonates, of lactate transport into rat erythrocytes. Identification of some new high-affinity inhibitors.
AuthorsPoole RC, Halestrap AP
JournalBiochem J
PubMed ID2025218
'1. Inhibition of L-lactate transport into rat erythrocytes by stilbenedisulphonates was studied under conditions which allowed the contribution of reversible and irreversible inhibition to be assessed. 2. At low temperatures (7 degrees C), 4,4''-di-isothiocyanostilbene-2,2''-disulphonate (DIDS) and other stilbenedisulphonates were found to inhibit lactate transport instantaneously, in a manner which was ... More
Trans to cis proton concentration gradients accelerate ionophore A23187-mediated net fluxes of Ca2+ across the human red cell membrane.
AuthorsVestergaard-Bogind B, Stampe P
JournalBiochim Biophys Acta
PubMed ID6432046
'Ionophore A23187-mediated net influx of Ca2+ in ATP-depleted human red cells was studied as a function of the pH and the proton concentration gradient across the membranes. Utilizing the Ca2+-induced increase in K+ conductance of the cell membranes, various CCCP-mediated proton gradients were raised across the membranes of cells suspended ... More
The location of a chymotrypsin cleavage site and of other sites in the primary structure of the 17,000-dalton transmembrane segment of band 3, the anion transport protein of red cell.
AuthorsRamjeesingh M, Rothstein A
JournalMembr Biochem
PubMed ID7176932
'A 17,000-dalton transmembrane segment of band 3 protein is further cleaved by chymotrypsin treatment of red blood cell ghosts to 15,000 daltons. The location of this particular chymotrypsin cleavage site was determined by comparing the fragmentation pattern of the 17,000- and 15,000-dalton peptides using cyanogen bromide (CNBr). Each peptide is ... More
The movement of fluorescent endocytic tracers in Plasmodium falciparum infected erythrocytes.
AuthorsHaldar K, Uyetake L
JournalMol Biochem Parasitol
PubMed ID1371847
'The fluorescent lipophilic probe 1,1''-dihexadecyl-3-3''-3-3''- tetramethylindocarbocyanine (diIC16) inserted in the red cell surface, functioned as a non-exchangeable lipid marker which was not metabolised or toxic in plasmodial cultures. Invasion by Plasmodium falciparum resulted in the internalisation of the lipid, suggesting the uptake of red cell membrane components during parasite entry. ... More
A pyruvate-proton symport and an H+-ATPase regulate the intracellular pH of Trypanosoma brucei at different stages of its life cycle.
AuthorsVanderheyden N, Wong J, Docampo R
JournalBiochem J
PubMed ID10657239
'Regulation of intracellular pH (pH(i)) and H(+) efflux were investigated in Trypanosoma brucei bloodstream and procyclic trypomastigotes using the fluorescent dyes 2', 7'-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF) acetoxymethyl ester and free BCECF respectively. pH(i) in bloodstream and procyclic trypomastigotes was 7.47+/-0.06 and 7. 53+/-0.07 respectively. Differences in the mechanisms for the regulation of ... More
Effect of atractylosides, palmitoyl coenzyme A, and anion transport inhibitors on translocation of nucleotide sugars and nucleotide sulfate into Golgi vesicles.
AuthorsCapasso JM, Hirschberg CB
JournalJ Biol Chem
PubMed ID6707004
'The effect of palmitoyl coenzyme A, atractylosides, and anion transport inhibitors on translocation into rat liver Golgi vesicles of adenosine 3''-phosphate 5''-phosphosulfate (PAPS), CMP-N-acetylneuraminic acid, and GDP-fucose was studied. Translocation of the above three nucleotide derivatives was inhibited by 4,4''-diisothiocyanostilbene-2,2''-disulfonic acid (DIDS; 50% inhibition required 10-20 microM DIDS). The inhibition ... More
Location of the stilbenedisulfonate binding site of the human erythrocyte anion-exchange system by resonance energy transfer.
AuthorsRao A, Martin P, Reithmeier RA, Cantley LC
JournalBiochemistry
PubMed ID497152
'The stilbenedisulfonate inhibitory site of the human erythrocyte anion-exchange system has been characterized by using serveral fluorescent stilbenedisulfonates. The covalent inhibitor 4-benzamido-4''-isothiocyanostilbene-2,2''-disulfonate (BIDS) reacts specifically with the band 3 protein of the plasma membrane when added to intact erythrocytes, and the reversible inhibitors 4,4''-dibenzamidostilbene-2,2''-disulfonate (DBDS) and 4-benzamido-4''-aminostilbene-2,2''-disulfonate (BADS) show a ... More
Inorganic anion transport in kidney and intestinal brush border and basolateral membranes.
AuthorsGrinstein S, Turner RJ, Silverman M, Rothstein A
JournalAm J Physiol
PubMed ID6247921
'The efflux of inorganic anions from purified brush border and basolateral membrane vesicles from dog kidney cortex was measured under equilibrium exchange conditions. Marked differences in temperature sensitivity and effects of inhibitors were found between the Cl and SO4 transport pathways and between the two types of membranes. SO4 transport ... More
Video-imaging micro-fluorometric assessment of luminal chloride/bicarbonate exchange activity in Madin-Darby canine kidney cells: influence of cell density, 4,4'-diisothiocyano-2,2'-disulfonic stilbene and acetazolamide.
AuthorsEbner S, Marin-Grez M
JournalBiol Chem Hoppe Seyler
PubMed ID8828818
'To investigate whether or not MDCK cells may be used as a model for beta-intercalated cells, we studied: (1) The effect of luminal [Cl-]0 changes on pHi measured by video-imaging micro-fluorometry, (2) the influence of the inhibitor 4,4''-diisothiocyano-2,2''-disulfonic stilbene (DIDS) on anion-exchange activity, and (3) the effect of acetazolamide on ... More
ATP-dependent transport of reduced glutathione on YCF1, the yeast orthologue of mammalian multidrug resistance associated proteins.
AuthorsRebbeor JF, Connolly GC, Dumont ME, Ballatori N
JournalJ Biol Chem
PubMed ID9837923
'The transport systems involved in the export of cellular reduced glutathione (GSH) have not been identified, although recent studies implicate a role for some of the multidrug resistance associated proteins (MRP), including MRP1 and MRP2. The present study examined the hypothesis that the yeast orthologue of MRP, Ycf1p, mediates ATP-dependent ... More
A novel UDP-Glc-specific glucosyltransferase catalyzing the biosynthesis of 6-O-glucosides of bile acids in human liver microsomes.
AuthorsRadominska A, Little J, Pyrek JS, Drake RR, Igari Y, Fournel-Gigleux S, Magdalou J, Burchell B, Elbein AD, Siest G
JournalJ Biol Chem
PubMed ID8325887
'Two active site-directed photoaffinity analogs, 5-[beta-32P]azido-UDP-glucuronic acid and 5-[beta-32P]azido-UDP-glucose, were used for the characterization of UDP-sugar-utilizing enzymes in human liver microsomes. Both compounds were recognized by human microsomal proteins: major photolabeled bands of 50-56 kDa were detected. Both photoincorporations were competitively decreased by increasing concentrations of either UDP-Glc or UDP-GlcUA, ... More
ATP-dependent acidification of membrane vesicles isolated from purified rat liver lysosomes. Acidification activity requires phosphate.
AuthorsSchneider DL
JournalJ Biol Chem
PubMed ID6218167
'Membrane vesicles were isolated from purified liver lysosomes of rats treated with Triton WR-1339. In order to preserve ATP-dependent acidification activity, proteolysis of membranes was minimized by adding protease inhibitors and by centrifuging to form dilute bands of vesicles rather than highly concentrated pellets. The membrane vesicle fraction represented about ... More
Mouse microglial cells express a plasma membrane pore gated by extracellular ATP.
AuthorsFerrari D, Villalba M, Chiozzi P, Falzoni S, Ricciardi-Castagnoli P, Di Virgilio F
JournalJ Immunol
PubMed ID8568257
'We have investigated responses to extracellular ATP (ATPe) in the microglial cell lines N9 and N13 and in freshly isolated mouse microglial cells. Upon stimulation with this nucleotide, N9 and N13 cells underwent an increase in the cytoplasmic free Ca2+ concentration ([Ca2+]i), a sustained depolarization of the plasma membrane, and ... More
The effect of 4,4'-diisothiocyanato-stilbene-2,2'-disulfonate on CO2 permeability of the red blood cell membrane.
AuthorsForster RE, Gros G, Lin L, Ono Y, Wunder M
JournalProc Natl Acad Sci U S A
PubMed ID9861053
'It has long been assumed that the red cell membrane is highly permeable to gases because the molecules of gases are small, uncharged, and soluble in lipids, such as those of a bilayer. The disappearance of 12C18O16O from a red cell suspension as the 18O exchanges between labeled CO2 + ... More
Functional geometry of the permeation pathway of Ca2+-activated Cl-channels inferred from analysis of voltage-dependent block.
AuthorsQu Z, Hartzell HC
JournalJ Biol Chem
PubMed ID11279188
'We examined the voltage-dependent block of Ca(2+)-activated Cl(-) channels by anthacene-9-carboxylic acid (A9C), diphenylamine-2-carboxylic acid (DPC), 4,4''-diisothiocyanostilbene-2,2''-disulfonic acid (DIDS), and niflumic acid (NFA) in excised inside-out and outside-out patches from Xenopus oocytes. The fraction of the voltage field (delta) experienced by the blocking drug was determined from the voltage dependence ... More
Development of H+ secretion by cultured renal inner medullary collecting duct cells.
'The purpose of these studies was to characterize the development of H+ secretion by cultured inner medullary collecting duct (IMCD) cells. Differentiated IMCD cells derived from rat papillae develop in culture N-ethylmaleimide (NEM)- and dicyclohexylcarbodiimide (DCCD)-sensitive Na+-independent H+ pump, but showed substantial heterogeneity. Cells with pHi greater than or equal ... More
Chemical modification and labeling of glutamate residues at the stilbenedisulfonate site of human red blood cell band 3 protein.
AuthorsJennings ML, Anderson MP
JournalJ Biol Chem
PubMed ID2879841
'A new method has been developed for the chemical modification and labeling of carboxyl groups in proteins. Carboxyl groups are activated with Woodward''s reagent K (N-ethyl-5-phenylisoxazolium 3''-sulfonate), and the adducts are reduced with [3H]BH4. The method has been applied to the anion transport protein of the human red blood cell ... More
Regulation of intracellular pH in rat lactotrophs: involvement of anionic exchangers.
AuthorsGarcia L, Boué-Grabot E, Garret M, Sartor P
JournalEndocrinology
PubMed ID9322929
'Regulation of the intracellular pH (pHi) of normal rat lactotrophs was studied. As this cell type, cultured with 10% FCS, can achieve a relatively alkaline pHi (7.3-7.5), we investigated the presence of a mechanism based on Cl-/HCO3- exchange. Using the pHi-sensitive probe SNARF-1 (seminaphtorodafluor) in its permeant form, SNARF-1/AM, we ... More
Role of anions in the regulation of cell volume and intracellular pH in perfused rat mandibular salivary gland.
AuthorsSeo JT, Kim YJ, Case RM, Steward MC
JournalPflugers Arch
PubMed ID9359905
'To investigate the role of Cl- in the regulation of the basolateral transporters of salivary acinar cells, we have measured cell volume and intracellular pH (pHi) in perfused rat mandibular glands using proton NMR spectroscopy and BCECF fluorometry respectively. When perfusate Cl- was replaced by glucuronate, isethionate, methylsulphate, nitrate or ... More
Identification of exchange mechanisms for the regulation of intracellular pH in rat thyroid FRTL-5 cells.
'pH is maintained in cells by plasma membrane exchange mechanisms. In the absence of HCO3- ions, FRTL-5 cells regulate intracellular pH (pHi) by an Na+/H+ antiport but HCO3(-)-dependent exchangers cannot operate. We have investigated pHi regulation (by microfluorimetry and the pH sensitive dye 2'',7''-bis(2-carboxyethyl)-5(6'')-carboxyfluorescein) in small groups (five to six ... More
Cys(577) is a conformationally mobile residue in the ATP-binding domain of the Na,K-ATPase alpha-subunit.
'2-[4''-Maleimidylanilino]naphthalene 6-sulfonic acid (MIANS) irreversibly inactivates Na,K-ATPase in a time- and concentration-dependent manner. Inactivation is prevented by 3 mM ATP or low K(+) (<1 mM); the protective effect K(+) is reversed at higher concentrations. This biphasic effect was also observed with K(+) congeners. In contrast, Na(+) ions did not protect. ... More
The Na/K/2Cl cotransporter is increased in hypertrophied vascular smooth muscle cells.
AuthorsTseng H, Berk BC
JournalJ Biol Chem
PubMed ID1569072
'Hypertrophy of vascular smooth muscle cells (VSMC) is a pathogenic feature of hypertension which may contribute to abnormal vessel tone and function. As a consequence of the increase in cell size associated with hypertrophy, it is likely that alterations in the mechanisms that regulate VSMC intracellular volume occur. Because the ... More
pH sensitivity of the Na+:HCO3- cotransporter in basolateral membrane vesicles isolated from rabbit kidney cortex.
AuthorsSoleimani M, Hattabaugh YJ, Bizal GL
JournalJ Biol Chem
PubMed ID1526975
'HCO3- exit across the basolateral membrane of the kidney proximal tubule cell is mediated via an electrogenic Na+:HCO3- cotransporter. We have studied the effect of pH on the activity of this cotransport system in basolateral membrane vesicles isolated from rabbit renal cortex. At constant internal pH 6.0, increasing the external ... More
Cloning and functional expression of a human kidney Na+:HCO3- cotransporter.
AuthorsBurnham CE, Amlal H, Wang Z, Shull GE, Soleimani M
JournalJ Biol Chem
PubMed ID9235899
'Several modes of HCO3- transport occur in the kidney, including Na+-independent Cl/HCO3- exchange (mediated by the AE family of Cl-/HCO3- exchangers), sodium-dependent Cl-/HCO3- exchange, and Na+:HCO3- cotransport. The functional similarities between the Na+-coupled HCO3- transporters and the AE isoforms (i.e. transport of HCO3- and sensitivity to inhibition by 4,4''-diisothiocyanatostilbene-2,2''-disulfonic acid) ... More
H+ and HCO3- flux across apical surface of rat distal colon.
AuthorsFeldman GM, Stephenson RL
JournalAm J Physiol
PubMed ID2164783
'Colonic ion transport is postulated to occur via simultaneous operation of Na(+)-H+ exchange and Cl(-)-HCO3- exchange. Accordingly H+ and HCO3- should be transported simultaneously by the colon. To assess simultaneous H+ and HCO3- transport, net acid-base flux was measured in isolated segments of rat distal colon. When both tissue surfaces ... More
The effects of anion transport inhibitors on structural transitions in erythrocyte membranes.
AuthorsSnow JW, Brandts JF, Low PS
JournalBiochim Biophys Acta
PubMed ID708734
'Red blood cell membranes have been labeled with several covalent and noncovalent inhibitors of anion transport and their heat capacity profiles determined as a function of temperature. Covalent inhibitors include the amino reactive agents 4,4''-diisothiocyanostilbene-2,2''-disulfonic acid, 4-acetamido-4''-isothiocyanostilbene-2,2''-disulfonic acid, pyridoxal phosphate and 1-fluoro-2,4-dinitro benzene. The non-covalent inhibitors include several well known ... More
Na(+)-H+ and Na(+)-dependent Cl(-)-HCO3- exchange control pHi in vascular smooth muscle.
AuthorsKahn AM, Cragoe EJ, Allen JC, Halligan RD, Shelat H
JournalAm J Physiol
PubMed ID2164779
'The mechanisms that control intracellular pH (pHi) in vascular smooth muscle are not fully understood. These studies were performed to determine the identity and relative importance of the sarcolemmal transport systems that mediate net acid efflux in primary cultured vascular smooth muscle cells from canine femoral artery. In HEPES- or ... More
Na-H and Cl-HCO3 exchange in rabbit oxyntic cells using fluorescence microscopy.
AuthorsParadiso AM, Tsien RY, Demarest JR, Machen TE
JournalAm J Physiol
PubMed ID3037913
'We have used the fluorescence intensity ratio (excitation 490/439; emission 520-550 nm) of 2'',7''-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF) to measure intracellular pH (pHi) in single oxyntic cells (OCs) within intact gastric glands isolated from rabbits. The fluorescence ratio was converted to pHi by exposing cells to high [K] Ringer plus 10(-5) M nigericin. ... More
Trapping of inhibitor-induced conformational changes in the erythrocyte membrane anion exchanger AE1.
AuthorsTang XB, Casey JR
JournalBiochemistry
PubMed ID10545179
'AE1, the chloride/bicarbonate anion exchanger of the erythrocyte plasma membrane, is highly sensitive to inhibition by stilbene disulfonate compounds such as DIDS (4,4''-diisothiocyanostilbene-2, 2''-disulfonate) and DNDS (4,4''-dinitrostilbene-2,2''-disulfonate). Stilbene disulfonates recruit the anion binding site to an outward-facing conformation. We sought to identify the regions of AE1 that undergo conformational changes ... More
Hypertonicity-induced intracellular pH changes in rat mast cells.
AuthorsCabado AG, Alfonso A, Vieytes MR, Botana LM
JournalLife Sci
PubMed ID11072873
'In a non-isotonic environment, cells can shrink or swell and return to their normal shape by activating ion transport pathways. Changes in intracellular pH (pHi) after osmotic stress have been identified in several cells. In order to study the mechanisms that regulate cytosolic pH of rat mast cells in a ... More
Tenidap and other anion transport inhibitors disrupt cytolytic T lymphocyte-mediated IL-1 beta post-translational processing.
AuthorsPerregaux DG, Svensson L, Gabel CA
JournalJ Immunol
PubMed ID8683156
'LPS-activated murine peritoneal macrophages produce IL-1 beta but externalize little mature cytokine in the absence of a secondary stimulus, and CTLs previously were reported to serve this capacity. The release of 17-kDa IL-1 beta from LPS-activated BALB/c macrophages occurred rapidly after the addition of C57/B1-derived allogeneic CTLs; within 30 min ... More
Interactions of the chelating agent 2,3-dimercaptopropane-1-sulfonate with red blood cells in vitro. I. Evidence for carrier mediated transport.
AuthorsWildenauer DB, Reuther H, Weger N
JournalChem Biol Interact
PubMed ID7151227
'Uptake of the water soluble 1,2-dimercaptopropanol (BAL) derivative 2,3-dimercapto-1-sulfonate (DMPS) into human red blood cells was found in vitro and the mode of penetration studied in detail. The compound entered erythrocytes in a concentration dependent manner. In contrast to sealed ghosts where inside and outside concentrations reached the same value, ... More
Lactic acid efflux from white skeletal muscle is catalyzed by the monocarboxylate transporter isoform MCT3.
AuthorsWilson MC, Jackson VN, Heddle C, Price NT, Pilegaard H, Juel C, Bonen A, Montgomery I, Hutter OF, Halestrap AP
JournalJ Biol Chem
PubMed ID9632638
'The newly cloned proton-linked monocarboxylate transporter MCT3 was shown by Western blotting and immunofluorescence confocal microscopy to be expressed in all muscle fibers. In contrast, MCT1 is expressed most abundantly in oxidative fibers but is almost totally absent in fast-twitch glycolytic fibers. Thus MCT3 appears to be the major MCT ... More
Functional coupling between a bafilomycin A1-sensitive proton pump and a probenecid-sensitive folate transporter in human placental choriocarcinoma cells.
AuthorsPrasad PD, Mahesh VB, Leibach FH, Ganapathy V
JournalBiochim Biophys Acta
PubMed ID8031869
'The mechanism of transport of 5-methyltetrahydrofolate, the predominant form of folate in human blood, was investigated in JAR human placental choriocarcinoma cells. Northern analysis revealed the presence of the folate receptor mRNA in these cells. Accumulation of 5-methyltetrahydrofolate in these cells was saturable and inhibited by other folate analogs. The ... More
Characterization of the stilbenedisulfonate binding site on band 3.
AuthorsSchopfer LM, Salhany JM
JournalBiochemistry
PubMed ID7599124
'Stilbenedisulfonates are potent inhibitors of Band 3 mediated anion exchange. They bind tightly to the protein and form a 1-to-1 reversible complex. Those stilbenedisulfonates which contain isothocyanato groups such as DIDS (4,4'-diisothiocyanato-2,2'-stilbenedisulfonate) and H2DIDS (4,4'-diisothiocyanatodihydrostilbene-2,2'-disulfonate) can also react rapidly with lysine residues within the binding pocket to yield an irreversible ... More
Transport of gamma-aminobutyrate and L-glutamate into synaptic vesicles. Effect of different inhibitors on the vesicular uptake of neurotransmitters and on the Mg2(+)-ATPase.
AuthorsFykse EM, Fonnum F
JournalBiochem J
PubMed ID1675566
'The uptakes of gamma-aminobutyrate (GABA) and L-glutamate into synaptic vesicles isolated from rat brain were compared with respect to the effects of 4-acetamido-4''-isothiocyanostilbene-2,2''- disulphonic acid (SITS), 4,4''-di-isothiocyanostilbene-2,2''-disulphonic acid (DIDS) and 5-nitro-2-(3-phenylpropylamino)benzoic acid (N144), agents known to block anion channels. The uptake of glutamate was inhibited by low micromolar concentrations of ... More
Cation depletion by the sodium pump in red cells with pathologic cation leaks. Sickle cells and xerocytes.
AuthorsJoiner CH, Platt OS, Lux SE
JournalJ Clin Invest
PubMed ID2430999
'The mechanism by which sickle cells and xerocytic red cells become depleted of cations in vivo has not been identified previously. Both types of cells exhibit elevated permeabilities to sodium and potassium, in the case of sickle cells, when deoxygenated. The ouabain-insensitive fluxes of sodium and potassium were equivalent, however, ... More
Cytosolic pH regulation in mouse macrophages. Characteristics of HCO3(-)-dependent mechanisms.
AuthorsTapper H, Sundler R
JournalBiochem J
PubMed ID1310007
'Mechanisms regulating cytosolic pH (pHi) in adherent resident mouse macrophages have been characterized by use of the pH-sensitive fluorescent probe 2'',7''-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF). Na+/H+ exchange was activated after an acid load of the macrophage cytosol. However, when Na+/H+ exchange was the only pHi-regulatory mechanism operative, recovery did not proceed beyond a ... More
Regulation of rabbit medullary collecting duct cell pH by basolateral Na+/H+ and Cl-/base exchange.
AuthorsBreyer MD, Jacobson HR
JournalJ Clin Invest
PubMed ID2547843
'The collecting duct of the inner stripe outer medulla (OMCDi) is a major site of distal nephron acidification. Using the pH sensitive fluorescent dye 2''-7''-bis(carboxyethyl)-5,6,-carboxyfluorescein (BCECF) and quantitative spectrofluorometry to measure intracellular pH in isolated perfused OMCDi, we have characterized basolateral transport processes responsible for regulation of intracellular pH. Experiments ... More
Characterization of the osteoclast ruffled border chloride channel and its role in bone resorption.
'Bone resorption by osteoclasts requires massive transcellular acid transport, which is accomplished by the parallel action of a V-type proton pump and a chloride channel in the osteoclast ruffled border. We have studied the molecular basis for the appearance of acid transport as avian bone marrow mononuclear cells acquire a ... More
Relationship of hepatic cholate transport to regulation of intracellular pH and potassium.
AuthorsVeith CM, Thalhammer T, Felberbauer FX, Graf J
JournalBiochim Biophys Acta
PubMed ID1730021
'Modulation of hepatic cholate transport by transmembrane pH-gradients and during interferences with the homeostatic regulation of intracellular pH and K+ was studied in the isolated perfused rat liver. Within the concentration range studied uptake into the liver was saturable and appeared to be associated with release of OH- and uptake ... More
Expression and function of bicarbonate/chloride exchangers in the preimplantation mouse embryo.
AuthorsZhao Y, Chauvet PJ, Alper SL, Baltz JM
JournalJ Biol Chem
PubMed ID7592657
'Bicarbonate/chloride (HCO3-/Cl-) exchangers regulate intracellular pH in the alkaline range. Previously, it has been shown that mouse embryos at the two-cell stage exhibit this activity, but that the otherwise ubiquitous mechanisms for regulating intracellular pH in the acid-to-neutral range are undetectable. We have examined mouse embryos during preimplantation development (one-cell ... More
Interactions of inhibitors on anion transporter of human erythrocyte.
AuthorsFröhlich O, Gunn RB
JournalAm J Physiol
PubMed ID3826335
'Chloride tracer efflux was measured from intact human erythrocytes into media containing different chloride concentrations and different concentrations of the inhibitors 4,4''-dinitrostilbene-2-2''-disulfonate (DNDS), N-(4-azido-2-nitrophenyl)-2-aminoethylsulfonate (NAP-taurine), phloretin, and sulfate. The data were analyzed to test whether these inhibitors were mutually exclusive with each other or whether they could bind at the ... More